Spring latch for stapler magazine and cover

ABSTRACT

For separably holding against relative swinging movement, two elements hingedly connected at one end, for example, the staple magazine and combined cover and staple driver of a stapler, a normally spring closed, manually openable latch includes keeper lugs projecting from the swinging end of the staple magazine and a latch lever hingedly mounted on the swinging end of the cover. A two-armed leaf spring has one arm secured on said cover adjacent said driver and its other end biasing said latch lever to interlock with said lugs, and said latch lever has finger tabs grippable between an operator&#39;&#39;s thumb and forefinger for releasing the latch and so located as to reduce possibility of inadvertent manipulation.

United States Patent [72] inventor William Leon Gay:

Summit, NJ.

121 1 Appl. No 850,111

221 Filed Aug. 14, 1969 14s 1 Patented July 20, 1971 [73] Assignee The Bates Manufacturing Company Orange, NJ.

(54] SPRING LATCH FOR STAPLER MAGAZINE AND 2,670,468 3/1954 Marano Primary Examiner-Granville Y. Custer, .lrv Attorney-Marry B. Rook ABSTRACT: For separably holding against relative swinging movement, two elements hingedly connected at one end, for example, the staple magazine and combined cover and staple driver of a stapler, a normally spring closed, manually openable latch includes keeper lugs projecting from the swinging end of the staple magazine and a latch lever hingedly mounted on the swinging end of the cover. A two-armed leaf spring has one arm secured on said cover adjacent said driver and its other end biasing said latch lever to interlock with said lugs, and said latch lever has finger tabs grippable between an operator's thumb and forefinger for releasing the latch and so located as to reduce possibility of inadvertent manipulation.

PATENTED JL|L20 I971 SHEET 2 BF 2 I N VEN TOR. [ff/am .Zeozz Gas a BY M ATTORNEY BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to spring closed manually openable latches and particularly latches for separably holding against relative swinging movement two hingedly connected elements for example, the staple magazine and combined cover and staple driver of a stapler.

2. The Prior Art The prior art includes such spring latches, the majority of which comprise a latch pin slidably mounted on one swinging element and spring biased into at least one notch in the other element, the latch pin being released either by camming action thereof or leveled walls of the notches under the force exerted to swing the elements apart or by manually sliding the pin out of the notches. The prior art latches leave much to be desired with regard to reliability and to ease of operation, and the pins can be easily inadvertently actuated to release the catch, during handling or normal operation of the elements so as, for example, in a stapler, to permit separation of the cover from the staple magazine.

SUMMARY A primary object of the present invention is to provide a latch of the type herein before described which includes a novel and improved construction and combination of relatively swingable elements for example, a staple magazine and cover of a stapler, a latch lever, keeper lugs and a spring, which shall be reliable and prevents or reduces the possibility of the inadvertent release of the latch during handling or operation of said elements.

More particularly, the invention contemplates a latch lever and lugs located at the outer ends of the swinging elements, instead of projecting from opposite sides of the elements; and the invention further provides a latch lever having one and end seated in fulcrum notches in one element, and a twoarmed leaf spring having one arm secured to said element and its other arm in separable engagement with said latch lever and biasing it to separably interlock with said lugs.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the invention, reference should be had to the following description in conjunction with the accompanying drawings in which:

' FIG. 1 a side elevation of a desk-type stapler having a latch embodying the invention;

FIG. 2 is a front end elevational view of the stapler;

FIG. 3 is a greatly enlarged fragmentary side elevation of the base and the relatively swinging ends of the stapler magazine and cover in separated relation to each other preliminary to the insertion of the staples into the magazine, portions of the hand piece being broken away for cleamess in illustration;

FIG. 4 is an enlarged front end elevational view of the staple magazine and cover in normal connected relation to each other, taken from the plane of the line 4-4 of FIG. 1 and with the hand piece broken away and shown in section;

FIG. 5 is a central vertical sectional view approximately on the plane of line 5-5 of FIG. and showing the hand piece.

FIG. 6 is a top plan view of the parts shown in FIG. 5 with the hand piece omitted,

FIG. 7 is a detached perspective view of the latch lever.

DESCRIPTION OF THE PREFERRED EMBODIMENT Refen'ing first to FIGS. 1, 2 and 3, the invention is shown as embodied in a stapler which includes a base A, a staple magazine B at one end of the base and a cover C therefor pivotally connected to each other at one end and to a bracket 1 on the base by apivot pin 2.

The staple magazine includes a casing 3 in which is a rail 4 for U-shaped staples that are pushed along the rail on one direction by a follower 5 which is actuated bya spring 6 mounted on a support rod 7. The magazine construction is generally known in the art and forms no part in the invention.

Associated with the magazine is a guide bar 8 which is pivotally mounted at one end of the pin 2 to overly the staples on said rail and has at its other end an extension 9 projecting into a slot 10 in one am 11 of a staple driver the other arm 12 of which is secured by a rivet 13 to the web portion 14 on an inverted channel of the cover C which has side flanges 15 to receive between them the magazine B when the magazine is connected to the cover as shown in FIGS. 1, 2 and 5.

The usual and generally known spring device 17 is interposed between base A and magazine B so as to normally swing the magazine upwardly away from anvil 18 on the base as shown in FIGS. 1 and 2. A leaf spring 19 has one end secured to the guide bar as by rivets 20 and its other end frictionally engaging the underside of the web portion 14 of the cover channel as best shown in FIG. 5. Said spring normally swings the channel cover away from the guide bar and such swinging is limited by engagement of the extension 9 with the end of the slot 10 in the driver. Movement of the cover channel and driver in the opposite direction against the influence of the spring 19 exerts through the spring 19 pressure on the guide bar 8 which in turn forces the magazine against the anvil 18 on the base. Continued movement in said direction then results in the actuation of the driver arm 11 so as to drive the leading staple through the work on the anvil.

In accordance with the invention a latch is provided for separably connecting the cover channel I4 to the magazine so that selectively the cover channel can be swung away from the magazine to permit loading of staples into magazine, or the cover channel can be connected to the magazine to hold the staples in place and to permit the whole stapler to be picked up and handled by manual gripping of the cover channel. Said latch is shown in the drawings as comprising a pair of keeper lugs 21 secured to and projecting from the swinging end of the magazine casing, said lugs preferably being formed on a plate 22 which is welded or otherwise secured to the end of the magazine casing. Cooperating with these lugs is a latch lever D which includes two parallel end bars 23 and 24 connected together by tie bars 25 as best shown in FIG. 7. The latch lever is hingedly connected to the cover so that the cross bar 24 is swingable into and out of engagement with the keeper lugs 21. As shown the cover channel has fulcrum notches 26 in which are loosely set the end portions 23a of the crossbar 23. The keeper is normally biased to interlock with the lugs 21, and as shown a two-armed leaf spring E has one arm secured to the cover between the web portion 14 of the cover channel and the arm 12 of the driver, the same rivet 13 serving to connect both the driver and the spring to the cover. Desirably the arm 12 of the driver has a notch 27 into which project a tongue 28 stamped from the web portion 14, so as "to prevent rotation of the driver on the rivet 13. It is also desirable that the end of the spring E abut said tongue to prevent rotation of the spring. The other arm 30 of the spring has an opening 31 into which projects a finger 32 projecting from the crossbar 24 of the latch lever. The spring is tensioned to normally urge the latch lever in the direction inwardly so that the keeper may ride over the beveled surfaces of the lug 21 as the cover is moved toward the magazine; thereafter the spring will move the keeper into interlocking relation to the lugs as shown in FIGS. 4 and 5. Movement of the lever by the spring is limited by engagement of the finger tabs 33 of the latch lever with abutment surfaces 38 on the ends of the cover channel flanges 15.

Preferably, as shown, the crossbar 23 is offset from the general plane of the latch lever and the crossbar 24 so that normally gravitational action tends to swing the lever in the direction to cause the crossbar 24 to become hooked under the keeper lugs 21.

The lever has a finger tab 33 projecting from each end of the crossbar 24 to be gripped between theoperators thumb and forefinger for releasing the latch. The finger tabs are located atthe outer end of the cover so there is a minimum possibility that the tabs will be pushed inadvertently to open the latch during normal handling and operation of the stapler, and to further protect the finger tabs the hand piece F, preferably formed of synthetic plastic material is fitted over the swinging end portion of the cover end channel so that the end'piece overlies the finger tabs and the sidewalls of the hand I piece are flush with or extend beyond the finger tabs as best shown in FIGS. 2, 5, and 4. The hand piece may be secured to the cover in any suitable manner but is shown as having a flange 34 which hooks under an overhanging ledge 35 on each flange of the cover channel, and lugs 36 may be also provided on the inner surface of the sidewalls of the hand piece to snap into notches 37 in the edges of the cover channel flanges The latch can be relied upon to positively but easily releasably connect the cover to the magazine. The latch itself must be positively operated to release it, but the operation requires almost no force or care, and the possibility of inadvertent release of the latch is reduced to the minimum.

1 claim:

1. In a stapling machine, the combination of a staple magazine and a cover therefor hingedly connected together at one end to enclose between them staples to be dispensed at their other swingable ends, a latch for separably connecting said magazine and cover at their second-mentioned ends,

comprising keeper lugs secured on said magazine and projecting from the swingable end thereof, a latch lever fulcrummed on said cover to be swung about an axis perpendicular to the plane of swinging of said magazine and cover into interlocking relation to said keeper lugs upon movement of said magazine and cover toward each other into one position and thereby hold them against swinging apart, said cover having a staple driver thereon, said latch lever having a crossbar at each end connected by ties bars, the croabar at one end having its end portions fulcrummed in notches in said cover and the other crossbar being adapted to hook under said keeper lugs, said latch lever being manually swingable about the fulcrums provided by said end portions of the crossbar in said notches out 4 of interlocking relation to said keeper lugs to permit said staple magazine and cover to be swung apart for loading with said staples.

2. The combination as defined in claim 1 with the addition of a leaf spring having one end connected to said cover and its other end engaging said latch lever to bias the latter in the direction to interlock with said keeper lugs.

3. The combination as defined in claim 1 wherein the second-mentioned crossbar extends parallel to the axis of swinging of said cover and staple magazine and has finger tabs at its ends for manipulation of the latch lever, and said cover has portions overhanging said finger tabs to protect them against inadvertent contact by an operator's fingers or by extraneous objects.

4. The combination as defined in claim 1 wherein said cover has a web portion and two side flanges depending therefrom, said notches are formed in the edges of said flanges, said staple driver is angle shaped with one arm secured to said web portion and another arm projecting from the web portion inwardly of said latch lever for driving staples, and with the addition of a two-armed leaf spring having one end secured to said web portion of the cover and its other arm projecting between said bars, and said latch lever has a finger projecting from the second-mentioned crossbar and engaged by the second-mentioned arm of the spring.

5. The combination as defined in claim 1 wherein said cover has a web portion and depending side flanges, said notches are formed in the edges of said flanges, and with the addition of a hand piece secured to said cover in overlying relation to the first-mentioned crossbar to hold said crossbar in said notches.

6. The combination as defined in claim 1 wherein said cover has a web portion and depending side flanges, said notches are formed in the edges of said flanges, and with the addition of a hand piece secured to said cover in overlying relation to the first-mentioned crossbar to hold said crossbar in said notches, said latch lever has finger tabs extending transversely of the plane of swinging of said cover and said magazine, and said hand piece overhangs said finger tabs to protect them against inadvertent manipulation. 

1. In a stapling machine, the combination of a staple magazine and a cover therefor hingedly connected together at one end to enclose between them staples to be dispensed at their other swingable ends, a latch for separably connecting said magazine and cover at their second-mentioned ends, comprising keeper lugs secured on said magazine and projecting from the swingable end thereof, a latch lever fulcrummed on said cover to be swung about an axis perpendicular to the plane of swinging of said magazine and cover into interlocking relation to said keeper lugs upon movement of said magazine and cover toward each other into one position and thereby hold them against swinging apart, said cover having a staple driver thereon, said latch lever having a crossbar at each end connected by ties bars, the crossbar at one end having its end portions fulcrummed in notches in said cover and the other crossbar being adapted to hook under said keeper lugs, said latch lever being manually swingable about the fulcrums provided by said end portions of the crossbar in said notches out of interlocking relation to said keeper lugs to permit said staple magazine and cover to be swung apart for loading with said staples.
 2. The combination as defined in claim 1 with the addition of a leaf spring having one end connected to said cover and its other end engaging said latch lever to bias the latter in the direction to interlock with said keeper lugs.
 3. The combination as defined in claim 1 wherein the second-mentioned crossbar extends parallel to the axis of swinging of said cover and staple magazine and has finger tabs aT its ends for manipulation of the latch lever, and said cover has portions overhanging said finger tabs to protect them against inadvertent contact by an operator''s fingers or by extraneous objects.
 4. The combination as defined in claim 1 wherein said cover has a web portion and two side flanges depending therefrom, said notches are formed in the edges of said flanges, said staple driver is angle shaped with one arm secured to said web portion and another arm projecting from the web portion inwardly of said latch lever for driving staples, and with the addition of a two-armed leaf spring having one end secured to said web portion of the cover and its other arm projecting between said bars, and said latch lever has a finger projecting from the second-mentioned crossbar and engaged by the second-mentioned arm of the spring.
 5. The combination as defined in claim 1 wherein said cover has a web portion and depending side flanges, said notches are formed in the edges of said flanges, and with the addition of a hand piece secured to said cover in overlying relation to the first-mentioned crossbar to hold said crossbar in said notches.
 6. The combination as defined in claim 1 wherein said cover has a web portion and depending side flanges, said notches are formed in the edges of said flanges, and with the addition of a hand piece secured to said cover in overlying relation to the first-mentioned crossbar to hold said crossbar in said notches, said latch lever has finger tabs extending transversely of the plane of swinging of said cover and said magazine, and said hand piece overhangs said finger tabs to protect them against inadvertent manipulation. 